I hope part of the plan is that if you refuse to answer a policeman's questions about your status, you are AUTOMATICALY arrested and deported if found to be an illegal alien.
And please stop using the term "illegal immigrant". They are "illegal aliens". They are not, by definition, immigrants.
Actually, the dictionary defines "immigrant" as
A person who leaves one country to settle permanently in another.Source: The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2000 by Houghton Mifflin Company. Published by Houghton Mifflin Company. All rights reserved.
That's why the adjective "legal" or "illegal" is appropriate.